The nucleotide sequence of bovine tRNA(Ser)UGA gene and its flanking sequences.
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Animals↗
Biomedical subjects
T S Stewart
Publications and source records attributed to T S Stewart.
Adapting best linear unbiased prediction (BLUP) for timely genetic evaluation: I. Progeny traits in a single contemporary group for each sex.
The first step of a procedure to partially circumvent the voluminous calculations with extremely large matrices for the usual algorithms for a BLUP (best linear unbiased prediction) approach is presented. This procedure, specific for a hierarchical portion of a model relevant to many animal breeding populations, is pertinent especially for polytocous species such as swine and poultry. For these, the occurrence of full-sib families makes the inclusion of dam effects in the model more necessary than in dairy or beef cattle models, where dam effects often are omitted. The formulas are derived for the hierarchical model for sires, dams within sires, individuals within full-sib family, and records within individuals, showing a relatively simple structure for such predictors. These formulas provide the basis for an alternative computing algorithm for obtaining evaluations having the statistical properties of best linear unbiased prediction. Formulas also are developed to approximate the prediction error variances for such models. Following this, the methodology for combining separate BLUP predictors, both error-independent and correlated, is developed.
Algorithms↗
Adapting best linear unbiased prediction (BLUP) for timely genetic evaluation: II. Progeny traits in multiple contemporary groups within a herd.
The second step of a procedure to partially circumvent the voluminous calculations for some BLUP (Best Linear Unbiased Prediction) computing algorithms for genetic evaluation is presented. In addition, the procedure allows timely evaluations of each contemporary group. This procedure is pertinent especially for polytocous species such as swine and poultry, for which the occurrence of full-sib families makes the inclusion of dam effects in the model necessary and tests are completed throughout the year. Formulas are developed for a model including sires, dams, individuals within full-sib families and records within individuals. This model has a fundamentally hierarchical structure but includes some cross-classification. The formulas for predictors combine information across contemporary groups within a herd and incorporate relationships between sires and(or) dams in that herd. Formulas to approximate prediction error variances also are developed.
Algorithms↗
Effect of birth and fraternal litter size and cross-fostering on growth and reproduction in swine.
Twelve hundred fifty-one pigs from six farrowings (FGRP) were classified within a FGRP by their birth litter size (BL- = below average and BL+ = above average), randomly allotted to nursing litter sizes of 6 or 12+ pigs/sow (NL- vs NL+) and reared by their own or foster dams (XF- vs XF+). Pigs were weighed at birth, 21 d and when near 105 kg. A random sample of 40 gilts per FGRP was retained for observation of pubertal age and primipara conception. Twenty-four gilts per FGRP were farrowed and rebred for a second parity. Pigs born in large litters were younger at 105 kg than those born in small litters (189 vs 196 d +/- 1.4); no other differences (P greater than .05) were observed for BL. Pigs reared in larger litters had lower survival rate from birth to weaning (79 vs 86% +/- 1), had slower weight gains to 21 d of age (5.3 vs 6.6 kg +/- .17) and were older at 105 kg (195 vs 190 d +/- 1.4) than those reared in small litters (P less than .04). Cross-fostered pigs were slower gaining to 21 d (5.9 vs 6.1 kg +/- .14) and were older at 105 kg (195 vs 191 d +/- 1.4) than pigs not cross-fostered pigs (P less than .02). Growth beyond 105 kg and pubertal age were unaffected by any factor studied (P greater than .05). Although size of birth litter did not affect (P greater than .05) any reproductive trait, an interaction between litter size and farrowing group was detected.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Multiple regression and principal components analysis of puberty and growth in cattle.
Multiple regression and principal components analyses were employed to examine relationships among pubertal and growth characters. Records used were from 424 bulls and 475 heifers produced by a diallel mating of Angus, Brahman, Hereford, Holstein and Jersey breeds. Characters studied were age, weight and height at puberty and measurements of weight and hip height from 9 to 21 mo of age; pelvic measurements of heifers also were included. Measurements of weight and height near 1 yr of age were related most highly to pubertal age, weight adn height. Larger size near 1 yr of age was associated with younger, larger animals at puberty. Growth rate was associated with pubertal characters before, but not after, adjustment for effects of breed-type. Principal components of the variation of pubertal and growth characters among animals were strongly related to both weight and height. The majority of the variation among breed-types was due to height. Characteristic vectors of principal components describing the variation of bulls and heifers were strikingly similar. The variance-covariance structure of pubertal characters was essentially the same for both sexes even though the mean values of the characters differed.
Animals↗
Methionine requirement of male white Pekin ducklings.
Two experiments were conducted to determine the methionine (Met) requirement of male White Pekin ducklings. In each study, day-old ducklings were raised in electrically heated battery brooders and fed a corn-peanut meal basal diet (dry mash) supplemented with either 0, .06, .12, .18, .24, or .30% L-Met. Based on the analysis of corn and peanut meal, the basal diet contained 22% crude protein .268% Met, and .284% cystine (Cys). The energy content of the basal diet was calculated to be 2914 kcal ME/kg. Regression analysis of 12- day weight gain data pooled across experiments indicated a quadratic trend. When the quadratic model was solved for 95% of maximum growth, a Met requirement of .422% was predicted (r2 = .49). Analysis of the pooled weight gain data by the broken-line method yielded a requirement estimate of .382% (r2 = .50). Therefore, the duckling's calculated Met requirement most likely lies between .382 and .422% (.666 and .706% total sulfur amino acids, respectively). This .04% discrepancy between models for predicting the duckling's Met requirement is probably of minor practical significance, considering the variability of Met and Cys contents of feedstuffs and the fact that corn-soy diets are usually supplemented with a source of Met activity that includes a margin of safety.
Animals↗
Point mutations in the 5' ICR and anticodon region of a Drosophila tRNAArg gene decrease in vitro transcription.
We have examined the effects of various nucleotide substitutions in a Drosophila tRNAArg gene on in vitro transcription and stable transcription complex formation in Drosophila KcO and HeLa cell extracts. Substitutions in positions encoding the invariant G18 and G19 residues resulted in decreased transcription, however, the moderate decreases indicate that these nucleotides are not obligatory promoter recognition sites. An A21 to C21 mutation had no effect on transcription levels using homologous extract however, this mutant displayed decreased transcriptional abilities in HeLa cell extract. Nucleotide substitutions within the sequence encoding the anticodon led to a decrease in the transcription activity but not in the ability to form a stable transcription complex.
Animals↗
Characterizing the function of O beta-phosphoseryl-tRNA.
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Animals↗
Maternal performance of Duroc, Hampshire and Landrace backcross gilts fed normal and high fiber diets during postweaning growth.
Duroc (DDDY), Hampshire (HHHY) and Landrace (LLLY) backcross gilts produced from matings of purebred sires and sixth or seventh parity F1 Duroc-Yorkshire, Hampshire-Yorkshire or Landrace-Yorkshire sows were fed and libitum either a high fiber (8.8% crude fiber, 2,910 kcal metabolizable energy (ME/kg) or normal fiber (3.9% crude fiber, 3,428 kcal ME/kg) diet during the postweaning growth period (70 to 170 d of age). A sample of 176 gilts was assigned randomly to one of three groups and exposed to purebred Yorkshire boars. All pregnant gilts were retained and exposed to boars for three additional production cycles. Sows failing to farrow were retained and returned to breeding with their contemporaries. Maternal performance, litter sizes at birth and weaning, pig weights, total litter weights and sow productivity index through four farrowings were not affected by postweaning dietary treatment of gilts. Interactions of nutritional regimen with either backcross type or exposure number were nonsignificant. Performances of the backcross types did differ. The DDDY had larger litter sizes at birth and weaning than HHHY or LLLY (12.0 vs 10.9 and 10.3 at birth and 9.6 vs 8.6 and 8.6 at weaning, respectively). Individual pig weights were similar at weaning among sow backcrosses. Therefore, DDDY females weaned heavier litters due to more pigs per litter and had higher sow productivity indices. Additionally, HHHY had a higher lactational weight loss and greater breeding and gestation weight gains than DDDY or LLLY. Sow feed consumption during lactation did not differ among backcrosses. Backcross type did interact statistically with sow group and exposure for several variables. Most significant interactions were due to differences in relative performance rather than absolute rank.
Animals↗
Factors associated with edema of the mammary gland in primigravid dairy heifers.
The severity and anatomical extent of mammary edema (edema) of 73 primigravid Holstein heifers was scored, and certain hormones in peripheral blood plasma were quantified. The objective was to obtain by least-squares analysis of covariance independent estimates of the association of each hormone and other factors with edema scores around first calving. Mammary edema prepartum increased with age of heifer and gestation length, decreased as calf birthweight increased, but was unrelated to seasonal fluctuations in temperature and photoperiod. The increase in edema during the last week of pregnancy was accounted for by associations with prepartum concentrations of hormones in plasma. The independent estimates of hormonal relationships to edema score prepartum were positive for plasma estrone and estradiol-17 alpha and were negative for plasma estradiol-17 beta and progesterone. Plasma prolactin was not related to edema score. After parturition, estradiol-17 beta was the only independent variable associated (negatively) with edema. The results indicate a complicated interaction among the sex steroids of late pregnancy wherein some steroids may promote edema and other steroids may inhibit edema in heifers.
Age Factors↗
Growth of fiber types and apparent fiber number in skeletal muscle of broiler- and layer-type chickens.
Proportions of myofiber types, radial growth (diameter) of myofibers and apparent myofiber number were measured at the midsection of the sartorius muscle of broiler- and layer-type chickens. Broiler birds grew mor rapidly than layer birds so that in comparisons at equal age, broilers had heavier body and muscle weights, larger diameter type I and II myofibers and greater apparent myofiber number. The proportion of type II red myofibers decreased and that of type II white myofibers increased during growth. These changes occurred at a younger age in broiler-type birds. At equal body weights, however, broiler- and layer-type birds had similar proportions of the various myofiber types, which indicates that development of myofiber types is affected by functional demands on skeletal muscle related to increasing body weight. At equal body weights, broilers had larger diameter type II myofibers than layers and had a more rapid rate of type II myofiber radial hypertrophy during growth. In contrast, layer-type birds had larger type I myofibers than did broilers and the rate of radial growth was similar between breeds. Apparent myofiber number per unit of body weight increased during growth at a similar rate in the two types of birds but broilers had greater numbers of myofibers. It was concluded that more rapid growth and greater muscularity of broiler-type birds are caused by more rapid myofiber hypertrophy and the presence of more myofibers. It is suggested that selection for growth and muscularity favors factors that promote selective radial hypertrophy of type II myofibers as seen in broiler-type chickens.
Animals↗
Variables associated with peripartum traits in dairy cows. IX. Relationship of season and other factors to blood plasma concentrations of progesterone and the estrogens.
Least-squares associations of month, average daily temperature, photoperiod (h daylight/24 h) and other factors with plasma concentrations of hormones during the prepartum period were examined in 172 Holstein cows and heifers. The data were summarized and expressed as values for prepartum d 7, 4 and 1, which represented the means for d 8 to 6, 5 to 3, and 2 to 0. respectively. All animals calved during a period of 19 consecutive months. Across days, least-squares means for plasma hormones were 4.0 ng/ml for progesterone (P4), 232 pg/ml for estradiol-17 beta (E beta), 478 pg/ml for estradiol-17 alpha (E alpha), 1,970 pg/ml for estrone (E1) and 2,680 pg/ml for total estrogen (TE; sum of E beta, E alpha and E1). Variations in plasma concentrations of certain steroids were associated (P less than .05 to P less than .01) with diet group (E beta), calf sex (TE), prepartum day (all hormones), month (E beta, E alpha) and linear covariates of cow weight (E beta, E alpha) calf birth weight (E beta, E alpha, E 1, TE), temperature (P4, E beta) and photoperiod (P4, E beta). The independent linear regressions for temperature and for photoperiod in prediction equations for each plasma hormone were always inversely related. The combined use of these regressions only partially accounted for fluctuations in the least-squares monthly means for hormones. Changes in least-squares monthly means for P4, E beta and E alpha tended to be only partially paralleled during the year. Nonparallel trends among hormones were most apparent during May to July (decreasing P4 but increasing E beta and E alpha), September to November (decreasing P4 and E beta but increasing E alpha) and January and February (only E alpha elevated). We hypothesize that seasonal differences in parturient traits reported for cows may be explained in part by the seasonally associated nonparallel changes in plasma concentrations of P4, E beta and E alpha.
Analysis of Variance↗
Beef X beef and dairy X beef females mated to Angus and Charolais sires II. Calf growth, weaning rate and cow productivity.
Preweaning growth of 814 progeny was studied, and weaning rate and kilograms of calf weaned/cow exposed were determined for 310, 2- to 7-yr-old angus x Hereford (AH), Charolais X Hereford (CH), straight bred Hereford (HH) and Brown Swiss X Hereford (SH) cows mated to Angus and Charolais bulls. Charolais-sired calves grew more rapidly (P less than .01) then Angussired calves were heavier (P less than .01) at 130 and 210 d of age. Progeny of SH females grew faster (P less than .05) and were the heaviest at 130 (164 kg) and 210 (231 kg) d, whereas calves from HH dams grew the slowest and weighed the least (P less than 0.5) at 130 (125 kg) and 210 (180 kg) d of age. Progeny from AH and CH dams had similar 130-d weights (CW130) and made similar daily gains from birth to 130 of age (ADGI). Calves from CH females gained faster (P less than .05) from 130 to 210 d (ADG2) and had higher (P less than .05) 210-d weights (CW210) than did calves from AH dams. ADG1 and ADG2 of male calves were .043 and .072 kg/d greater, respectively (P less than .01) than those of heifer calves. Age of dam influenced (P less than .01) calf preweaning gains and weights. Calves from 4- to 7-yr old cows had greater (P less than .05) ADG1 and ADG2 and higher (P less than .05) CW130 and CW210 than progeny of younger dams. Progeny of 2-yr-old cows grew more slowly (P less than .05), and were last (P less than .05) in all traits (ADG1, ADG2, CW130 and CW210), whereas progeny of 3-yr-old cows were intermediate to those of 2 and 4- to 7-yr-old females. Cow breed type influenced (P less than .01) weaning rate (WR) and kilograms of calf weaned/cow exposed. SH females has the highest WR (83.4%), AH and CH were intermediate at 76 .8 and 77.7%, respectively, and HH dams had the lowest (P less than .05) WR, 66.4 calves/100 cows exposed. SH cows weaned 34.6 kg more (P less than .05) calf/cow exposed than AH and CH dams. HH dams were least productive (P less than .05), weaning 122.3 kg calf/cow exposed. Dairy X beef dams (SH) weaned 47.6 kg more (P less than .01) calf/cow exposed than the average of beef X beef dams (AH, CH, HH). Dairy X beef females had the highest WR and weaned the heaviest calves.
Animals↗
Relationships of hormones, temperature, photoperiod, and other factors to voluntary intake of dry matter in pregnant dairy cows prior to parturition.
Voluntary intake of dry matter per 100 kg body weight (defined as intake) was quantified in 86 pluriparous Holstein cows which calved during 19 consecutive mo. Least squares techniques were used to examine the association of intake during the last 8 days before calving with numerous independent variables representing seasonal and physiological factors. The data were summarized as prepartum days 7, 4, and 1 (means of days 8 to 6, 5 to 3, and 2 to 0, respectively). Intake was lowest on prepartum day 1. Main effects of diet-group, health status, and month were not related significantly to intake when covariates were included in the statistical model. Intake decreased with increasing age of cows, but it was not related independently to body condition score. There were seasonal variations in intake which could be accounted for statistically by either month as a main effect or by quantitative indices of seasonality (temperature, photoperiod, plasma prolactin). Intake was lowest in February, June, and July and highest in October. Calf birthweight was related to intake in an unexpected manner. Intake was lowest in dams carrying either small or large calves. Prolactin of plasma was associated independently with intake, but this hormone may be just another measure of seasonal variation. All variables accounted for 58% of the total variance in intake. When seasonal variations in intake were accounted for statistically by other variables, none of the steroid hormones (progesterone, estrone, estradiol-17 beta, and estradiol-17 alpha) were associated independently with variation in voluntary intake. Associations of cow age and of climatic indices with intake were greater during days 7, 4, and 1 prepartum as compared to day 250 of gestation, days .5 to 2.5 postpartum, and days 3 to 30 of lactation.
Animal Feed↗
Mature weight, maturation rate, maternal performance and their interrelationships in purebred and crossbred cows of angus and milking shorthorn parentage.
Mature weight, maturation rate and lifetime maternal performance, through a maximum of seven calving seasons, were analyzed for 182 cows of Angus (A) and Milking Shorthorn (S) breeds and the two reciprocal crossbred groups. Mature weight and rate of maturation were estimated for the three-parameter growth curve described by Brody. Estimates derived for mature weight (kilograms), both unadjusted and adjusted for cow condition, were, respectively: Angus, 421, 407; Shorthorn, 409, 459; A x S, 448, 455 and S x A, 440, 441 (approximate standard error, 8 kg). Estimates for the maturation rate parameter were, respectively: Angus, 5.8, 6.3; Shorthorn, 6.6, 5.4, A x S, 6.2, 6.1 and S x A, 5.9, 6.1%/month (approximate SE, .3%/month). Heterosis for mature weight was 3 to 7% (28 +/- 8 and 15 +/- 6 kg, respectively). No heterosis was observed for the maturation rate parameter. Birth weight (.048 +/- .025 kg/kg) and weaning weight (.142 +/- .044 kg/kg) of the first calves were positively related with mature size of the dam. Weaning weights of first calves increased with increasing rate of maturation of the dams (3.6 +/- 1.5 kg/percentage/month) while birth weights remained unchanged. Under the culling criteria used in this study, the number of calves produced by a cow in her lifetime decreased (-.007 +/- .003 calves/kg) with increasing mature weight, while average weaning weight of the calves increased (.132 +/- .03 kg/kg). Total weight weaned, years in the herd and weight weaned per year tended to decrease (P greater than .05) with increasing mature weight of dam, but not significantly. Positive heterosis was expressed for all lifetime cow productivity characters, with crossbred cows weaning 22% (230 +/- 57 kg) more calf weight in their lifetime.
Animals↗
Nucleotide sequence of Lactobacillus viridescens 5S RNA.
The nucleotide sequence of Lactobacillus viridescens ATCC 12706 5S RNA was determined to be pU-G-U-U-G-U-G-A-U-G-A-U-G-G-C-A-U-U-G-A-G-G-U-C-A-C-A-C C-U-G-U-U-C-C-C-A-U-A-C-C-G-A-A-C-A-C-A-G-A-A-G-U-U-A-A-G-C-U-C-A-A-U-A-G-C-G C-C-G-A-A-A-G-U-A-G-U-U-G-G-A-G-G-A-U-C-U-C-U-U-C-C-U-G-C-G-A-G-G-A-U-A-G-G-A C-G-U-C-G-C-A-A-U-G-COH. When compared with other published sequences of prokaryotic 5S RNA species, this sequence shows as much homology with that from B. substilis (80% homology when all variations included) and B. megaterium (77% homology) as with the 5S RNA from another member of Lactobacillaceae family (L. brevis, 79% homology). The sequence contains the proposed tRNA binding site (CGAAC, positions 41-45) and can accomodate most, but not all, of the more recently proposed helical regions of secondary structure.
Bacillus megaterium↗
Characterization of cattle of a five-breed diallel. III. Puberty in bulls and heifers.
Pubertal characters of bulls and heifers produced in a diallel mating of Angus, Brahman, Hereford, Holstein and Jersey cattle were analyzed. Ninety-one heifers and 138 bulls in individual pens adn 286 bulls in drylots were fed a 72% TDN diet ad libitum; another 384 heifers were placed on pasture with supplemental feed. Puberty in heifers was defined as time of first ovulatory estrus; in bulls, as first detection of sperm cells in an electroejaculate. Breed type least-squares means, adjusted for birth month, were estimated within sex-nutrition-management groups and then decomposed into breed effects, average heterosis (h), general combining ability (GCA) and specific combining ability (SCA) by diallel analysis techniques. Breed effects were a significant source of variation for all characters studied. Heterosis (h, GCA, SCA) was not significant for pubertal age of bulls or heifers receiving complete diets in pens, a rather high nutritional plane. However, on pasture, crossbred heifers reached puberty at a younger age (P less than .05) than straightbreds. Average heterosis was significant (P less than .05) for increased weight and hip height at puberty and ratios involving these characters for both sexes. Specific combining abilities were not statistically significant for the majority of the pubertal characters, yet large differences among estimates of combining abilities were expressed. Ad libitum feeding of the penned heifers tended to decrease pubertal age and increase pubertal size as compared to pubertal age and size of pastured heifers. The breed type x management interactions within both sexes indicated a different ranking of the breed types for each management regimen.
Animals↗
Influence of dietary calcium and protein on fecal pH, consistency, and rate of passage in dairy cattle.
Sixteen Holstein heifers and 20 calves were in trials on the effect of 10 and 15% crude protein and .3 and .9% calcium in the diet on fecal pH and consistency and on rate of passage of the liquid phase of digesta. Time of first appearance of polyethylene glycol was an indicator of rate of passage of the liquid phase in the lower tract of the animal. Respective fecal pH and standard errors for heifers and calves increased from 5.79 +/- .03 and 5.78 +/- .03 on low calcium diets to 6.24 +/- .03 and 6.33 +/- .03 on high calcium diets. High protein diets increased fecal pH from 5.89 +/- .03 and 5.97 +/- .03 to 6.13 +/- .03 and 6.14 +/- .03 for heifers and calves. Effects of calcium and protein were additive. Neither dietary protein nor calcium affected consistency of feces or first appearance of polyethylene glycol in feces. Mean first appearances of PEG in feces were 683 +/- 13 min for heifers and 528 +/- 18 min for calves. Small correlations between fecal pH and fecal consistency and between fecal pH and first appearance of polyethylene glycol in feces indicate little or no relationship of fecal pH to these two variables. From variance in the heifer trial, 10 fecal samples are required to estimate fecal pH within +/-.16 pH units with 95% confidence.
Animals↗